Electrical connector with insulation piercing means



Dec; 8,1970 K. WILHELM ETAL Y 3,546,660

. ELECTRICAL CONNECTOR WITH INSULATION PIERCING MEANS Filed Feb. 10,1969 Fig. l

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5 2 Mou flL-horneg United States Patent Ofi ice US. Cl. 339-94 8 ClaimsABSTRACT OF THE DISCLOSURE A connector arrangement for cables having anelectrical conductor and insulation surrounding the conductor, theconnector arrangement incorporating two half-shells each having an innersurface which engages the insulation of a cable between the half-shells.The half-shells have inwardly extending, pointed prongs which, duringplacement of the half-shells on the cable, penetrate the insulation andpierce into the electrical conductor. The half-shells have externalthreads at their ends, so that, when the two half-shells are in place,they together form a composite tubular body which is externally threadedat each end. Two cap screws are provided, each having an internallythreaded tubular portion, these cap screws being threaded onto oppositeends, respectively, of the composite tubular body constituted by thehalf-shells. Sealing means are provided between the cap screws and thecomposite tubular body constituted by the half-shells.

BACKGROUND OF THE INVENTION The present invention relates to cableconnectors for use with cables of the type having an insulatedelectrical conductor, made, for example, of an alkali metal such assodium. The connectors themselves are made, at least in part, ofelements which themselves are made of a material which is a goodconductor of electricity and which are indirect contact with theelectrical conductors.

There exists a conductor arrangement in which the connector is providedwith a sleeve, closed at one end, within which there is arranged acorkscrew-like thread which is threaded into the electrical conductor.The drawback of this arrangement is that it is either not possible, orpossible only with great difliculty, to seal a, cable which is equippedwith this type of connector. A further drawback of this type ofconnector arrangement is that, in order to secure it to a cable, one hasto use a special crimping tool. Yet another drawback of the describedarrangement is that, while it is suitable for being connected to onecable end, it can not be converted for use as a connector to join twocable ends to each other, nor can it be converted for use as a connectorto tap a branch 01f the cable; instead, if two cable ends are to bejoined to each other, two connectors are required, and if a branchtypeconnection is to be made, three connectors are. required. This, in turn,means not only that a relatively large number of connector elements haveto be used, but also, that special care must be taken to make certainthat the connectors are themselves in proper electrical contact witheach other.

It is, therefore, the primary object of the present invention to providea connector arrangement which overcomes the abovedescribed drawbacks.

SUMMARY OF THE INVENTION With the above object in view, the presentinvention resides, basically, in a connector arrangement for cableshaving an electrical conductor and insulation surround- Patented Dec. 8,1970 ing the conductor, the connector arrangement incorporating twohalf-shells each having an inner surface which engages the insulation ofa cable between the half-shells. 'Ihe half-shells have inwardlyextending, pointed prongs which, during placement of the half-shells onthe cable, penetrate the insulation and pierce into the electricalconductor. The half-shells have external threads at their ends, so that,when the two half-shells are in place, they together form a compositetubular body which is externally threaded at each end. Two cap screwsare provided, each having an internally threaded tubular portion, thesecap screws being threaded onto opposite ends, respectively, of thecomposite tubular body constituted by the half-shells. Sealing means areprovided between the cap screws and the composite tubular bodyconstituted by the half-shells.

The cap screws may be made of insulating or non-insulating material; ifthey are made of plastic, the sealing means may be integral with thescrew caps.

According to another feature of the present invention, the ends of thecomposite tubular body may be cylindrical or they may be conical.

According to still another feature of the invention, one of the capscrews may extend as far as the other cap screw, and surround and be inthreaded engagement with this other cap screw.

BRIEF DESCRIPTION OF THE DRAWING embodiment of a cable connectoraccording to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to thedrawing and first to FIG. 1 thereof, the same shows the end 1 and 2 oftwo cables which are to be connected to each other. The cablesthemselves are made, for example, of a metallic conductor such assodium, surrounded by insulation such as a polyolefin. The connectorarrangement comprises two cap screws 3 and 4 and associated sealingrings 5 and 6 which are slipped over the respective cable ends. Thelatter are then brought into alignment with each other and moved into aposition where they almost touch each other, there being suitablesealing means between the cable ends, such as a sealing ring 12 which isplaced between the end surfaces of the cable ends, or a foil (not shown)which is wound about the two cable ends. Two half-shells 7 and 8, eachmade of metal or other material that is a good conductor of electricityand provided with internally extending, conical prongs 9, are thenpressed, from the side, against and into the cable ends, such that thepoints of the prongs 9 penetrate through the insulation 10 and pierceinto the conductor 11. Thanks to the conical configuration of the prongs'9, there is established both excellent electrical contact with theconductors 10 as well as an excellent seal with respect to the outside.

The half-shells 7, 8 are provided, at their respective outer ends, withthreads which mate with internal threads with which the tubular portionsof the respective cap screws 3, 4 are provided. The ends of the shells,and the associated threading, may be cylindrical, as shown in FIG. 1, orconical, with the threading tapering toward the tips, as shown in FIG. 2where one of the two cap screws is indicated at 103 and the half-shellsat 107 and 108.

When the two half-shells 7, 8 are pressed into the cable ends untiltheir inner surfaces almost engage the outer surfaces of the insulation10, they form a composite tubular body which is externally threaded ateach end. The two cap screws 3 and 4, together with their sealing rings5 and 6, are threaded onto the composite tubular body constituted by thehalf-shells, thus pressing the prongs 9 into the conductor 11. If thehalf-shells are conical as shown in FIG. 2, they will be pressed evenmore tightly against the insulation 10. The longitudinal gap at betweenthe half-shells will then be closed, i.e., the half-shells will bepressed until their longitudinal edges engage each other, or if there isstill a space between the half-shells, the same will be filled by thematerial of the insulation 10, or the foil which is wound about thecable may be pressed into the gap. In this way, the connection as awhole is provided with a seal in addition to that afforded by the rings5, 6.

The cap screws 3, 4 may themselves be made of metal or other materialwhich is a good conductor of electricity. Alternatively, the cap screwsmay be made of plastic, as shown in FIG. 2, in which case the sealingmeans 105 may be integral with the cap screw 103. One significant andpractical advantage of making the cap Screws of plastic is that the samemay initially be made without any hole in the bottom, since it is verysimple to provide an otherwise finished cap screw with whatever diameterhole is needed to accommodate the particular cable with which the capscrew is used, and this, in turn, reduces the necessity of maintainingan extensive inventory consisting of prepunched cap screws having holesof various diameters. Here it will be noted that cap screws having nohole in their bottom will serve to close oif a cable end completely andcan thus be used as a terminal cap. Terminal caps made of metal, on theother hand, have the advantage that they can easily be provided with aconnecting stud prior to being assembled in the connector arrangement.

FIG. 3 shows a modified embodiment of the present invention in which thecap screw 204 is provided with a tubular extension 204a, the latterbeing internally threaded at least in the region of its free end, thisthread mating with an additional external thread on the tubular portionof the cap screw 203, so that the cap screw 204 canactually be threadedonto the cap screw 203. In this way, a still greater axial pressure canbe exerted, thereby producing a still better seal between the partsbeing connected.

It will be appreciated that, thanks to the abovedescribed arrangement,there is provided a connector arrangement which is composed ofindividually uncomplicated parts. The half-shells may be readilyconfigured so as to be suitable for use as a means for joining two cableends to each other, or as a terminal connector, or

as a branch connector.

It will be understood that the above description of the presentinvention is susceptible to various modifications, changes andadaptations. For example, the embodiment shown schematically in FIG. 3may incorporate any of the structural features shown in and described inconnection with either or both of FIGS. 1 and 2, e.g., the arrangementshown in FIG. 3 may be used in conjunction with half-shells havingcylindrical or conical ends, or the cap screws themselves may be made ofplastic and have the sealing means integral therewith, or the cap screwsmay be made of metal with separate sealing rings being provided.

We claim:

1. A connector arrangement for cables having an electrical conductor andinsulation surrounding the conductor, the connector arrangementcomprising, in combination:

(a) two half-shells each having an inner surface which engages theinsulation of a cable between said halfshells, said half-shells havinginwardly extending pointed prongs which, during placement of saidhalfshells on the cable, penetrate the insulation and pierce into theelectrical conductor, said half-shells having external threads at theirends, said half-shells together forming a composite tubular body whichis externally threaded at each end;

(b) two cap screws each having an internally threaded tubular portion,said cap screws being threaded onto opposite ends, respectively, of saidcomposite tubular body constituted by said two half-shells; and

(c) sealing means between said cap screws and said composite tubularbody constituted by said halfshells.

2. A connector arrangement as defined in claim 1, wherein said capscrews are made of a material which is a good conductor of electricity.

3. A connector arrangement as defined in claim 2, wherein said sealingmeans comprise sealing rings each interposed between the inner bottomsurface of a respective cap screw and the corresponding ends of saidhalfshells.

4. A connector arrangement as defined in claim 1, wherein said capscrews are made of insulating material.

5. A connector arrangement as defined in claim 4, wherein saidinsulating material is a plastic and said sealing means are integralwith said cap screws.

6. A connector arrangement as defined in claim 1, wherein said ends ofsaid composite tubular body are cylindrical.

p 7. A connector arrangement asdefined in .claim 1, wherein said ends ofsaid composite tubular body are conical and taper toward the tips ofsaid composite tubular body.

8. A connector arrangement as defined in claim 1, wherein the tubularportion of one of said cap screws is externally threaded and the tubularportion of the other of said cap screws extends axially to surround thetubular portion of said first cap screw and. is in threaded engagementwith the external thread of said first cap screw.

References Cited UNITED STATES PATENTS 1,488,636 4/1924 Geiser 339-981,980,893 11/ 1934 Walde 33997X 2,725,545 11/1955 Gordon 339-993,041,575 6/1962 Schneider 339-268X 3,417,195 12/1968 Shlesinger 339-XFOREIGN PATENTS 1,495,934 8/1967 France 339-97 MARVIN A. CHAMPION,Primary Examiner I. A. CALVERT, Assistant Examiner US Cl. X-R.

